AR15.Com - Your Firearm Resource. (AR-15, AR-10, M4 Carbine, M16, H&K, SIG, FNH, FAL, AK-47, 50 Cal, M1/M1A, Handgun, Pistol, Training, Hunting, and More!) is a pretty big forum. i don't post there but my dad does quite a bit, i'd check it out.

 

The barrel is a M4 profile which means its a 16".
The barrel extension is what goes into the receiver, it has the locking lugs that the bolt rotates in and locks up. ( like closing the bolt on a bolt action)
And it also has the feed ramp cuts so the bullets dont have a edge to grab on.

Ever seen how the diameter of the barrel changes. Where it has a step down and then steps back up before the muzzle. Thats whats considered the M4 profile haha

 

You gotta watch AR15.com
Theres a bunch of mall ninjas over there.
Bunch of good info over there. But you gotta wear your waders and carry a sifter. If that makes since.

 

^this is very true and that's Why I don't post there...lots of good links and information there, but it has the common over populated message board symptoms pretty bad

 

Thanks for the help!

Just looking around that site, you guys were right, it's bad over there. It looks like it might take more time to weed through the BS, then to find good info.

 

Check their site sponsors and stickies if they have any...that'd be your best bet I think

 

Sorry double post I'm on my phone can't edit...my AR is built off a superior arms lower which I got stripped and pieced together. They arent too difficult if you have experience assembling and reassembling different guns But there are a couple tricky parts so if you're inexperienced then you should get an assembled lower.

 

brownells has how to vids, that's what I used, I now have a book. Well, photocopied book from an armorer friend, I need to get it scanned so I can send it out to people.

 

If you got any problems or questions, a few of us have enough experience with ARs we should be able to help ya.
They are very simple to work on once you figure out whats goin on .